1. Field of the Invention
This invention relates to a card reader protecting device, and more particularly to a protecting device for preventing any card other than a normal card from being inserted into the card reader provided in a cash dispenser and the like.
2. Description of the Prior Art
Magnetic lock, which permits only a right person identified by a magnetic card to perform a desired operation thereof, is now used for locking the door of a safe, a laboratory or a cash dispenser for automatic payment of cash, since the magnetic lock has such advantages that it is excellent in security and secrecy, and in addition, the magnetic card used in cooperation with said magnetic lock is suitable for portability and usability of card in combination, for example with ID card and the like. In other words, almost numberless keys may be produced by use of key codes variable only little by little. Furthermore, as electrical signals are produced when card codes are read, it is possible to record cash payment such as amount of payment, date of payment etc. or to obtain recording as to door operation such as a frequency of opening and closing door, time at the operation of the door and operators or users identification by means of reading personal codes. Still furthermore, key codes may be hardly copied by a third person due to unreadability thereof in magnetic cards under normal conditions. Such a device as to permit the reading of any necessary information out of a magnetic card is called generally a card reader. In this invention the word "card" means a recording medium in a broader sense in view of possible substitution of the card by any other same type of recording medium.
Now such a card reader must be protected against possible use intentional or accidental of any wrong card. Here the wrong card means not a card with a wrong key code number (which may be found in code reading) but any card specified for other devices or a name card. For example, if a card short in length is used, it cannot be taken out as it remains beyond feed rollers. (Generally a card carried through such feed rollers may be fed back by reverse running of a motor controlled by a microswitch for reverse motor operation provided in inner position and actuated when it is struck before the card leaves the feed rollers.) If a card much thinner than a normal card is used, jamming may occur, and if a card too wide is used, it may fail to move on in the entrance. In some cases the function may get out of order as a result of clogging a slot with butt, paper trash, chewing gum or other foreign material by wanton mischief. Thus, whenever any wrong card of no standards or any foreign substance is found by means of a detector of card authenticity, before the card slot that is, before a card reader section including card feed rollers, reading head etc., their farther insertion must be prevented.